B1051 Mitsubishi Libero Diagnostic Trouble Code

B1051 Mitsubishi Libero code definition:
B1051 is a kind of OBD-II Diagnostic B-Body Diagnostic Trouble Code for Mitsubishi Libero.

B1051 Mitsubishi Libero is triggered when the bank 1 camshaft position sensor doesn't match the signal from the crankshaft position sensor. The spark should have a light tan color. If the sensor probe comes with white and chalky parts, this means it has been lagging between switching phases, and should be replaced.

Symptoms

Symptoms of a B1051 Mitsubishi Libero diagnostic trouble code may include:

Engine surge
Blown fuse (if applicable)
Lack of power
Rich or lean exhaust

Possible Causes :

Faulty IMRC actuator relay (if equipped)
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Common Misdiagnoses

IC Circuit High Voltage Problem
Control Module Throttle Actuator Position Performance Problem
Air Conditioning (A/C) Clutch Feedback Circuit High Voltage Problem
Cruise Vehicle Speed/Set Speed Difference Too High Problem
PCM Stack Overrun Problem

Repair Processes :

If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. Look at the plug wires to make sure they are not burnt or laying on the exhaust.

Process Tips

Diagnostic trouble code B1051 Mitsubishi Libero is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before B1051 Mitsubishi Libero.

Fortunately, B1051 Mitsubishi Libero is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.